1. Technical Field
The present invention relates in general to manipulating a screw and, more particularly, to device for use with a torque driver for engaging the head of a screw and picking up the screw.
2. Description of the Related Art
In manufacturing industries, different parts of a product under manufacture are often held together or fastened by means of screws. The parts to be fastened typically contain corresponding holes with screw threads for receiving the screws, the screws also having reciprocating screw threads. The screws are inserted into these screw holes and then threadingly engaged. When the screws are tightened, the parts are held together by these screws.
While fastening things using screws, many problems may occur. For example, if the screws are not inserted perpendicularly into the screw holes, the screw threads on either or both of the screw holes and screws may be damaged when the screws are tightened. This is because the screw threads on the screw may cut the screw threads in the screw holes, or vice-versa, in a process known as cross-threading, thereby causing the damage. Other examples of problems that may arise when fastening things using screws relate to the picking up of the screws. Screws may be picked up manually by an operator, or using a tool that the operator may also use for tightening the screws. In a conventional tool for picking up screws, magnetic means or suction means may be used. In relation to conventional tools using the suction means, one problem that may arise concerns the size and/or weight of the screw. Screws vary in type and sizes. Such conventional tools, however, may not adequately enable the operator to pick up larger and heavier screws. This is because the suction means is dependent on vacuums in the conventional tools, and the vacuums are in turn produced by air removal devices that are attached to the conventional tools. If an air removal device is not powerful enough, the vacuum produced may not enable the operator to pick up larger and heavier screws. On the other hand, if the air removal device is provided with increased power to enable the conventional tools to pick up the larger and heavier screws, the effect might be undesirable as screw release or drop-off operations may be harder to control. Alternatively, if there is sudden loss of vacuum due to a fault or inconsistency in the air removal device, a screw being picked up may be dropped by the attached conventional tool. Hence, even the smallest screw may not be picked up in this circumstance.
In relation to conventional screw pick-up tools that utilize magnets or apply magnetic fields, an attendant problem that is important is the limitation of the effect of such conventional tools on non-austenitic metal. Austenitic metals, that is, metals formed largely of stainless steel, are not affected by magnets or magnetic fields. Hence, the conventional tools using magnetic means cannot be used to pick up Austenitic screws. In some manufacturing industries, it is important to use stainless steel screws as fasteners. Hence, in such manufacturing industries, such conventional tools become ineffective as screw pick-up tools. Even in the case of non-Austenitic screws, such conventional tools remain ineffective as screw pick-up tools since the magnetic means do not provide a stable hold on the non-Austenitic screws.
In manual screw pick-up and tightening operations, operators typically pick up the screws manually before feeling and orienting the screw heads for engagement with a screw-driving tool. The operator using the screw-driving tool subsequently drives the screws into the visually located screw holes. For apparent reasons contributed by the dexterity, alertness, and the like acuity attributes of the operator, the manual screw pick-up and tightening operations are highly susceptible to problems like cross threading. Even with the use of the conventional pick-up tools mentioned in the foregoing, there still exist manifold problems because these conventional pick-up tools have inherent inadequacies.
In unique or special manufacturing conditions, stringent requirements for the screw tightening operations exist. For example, in the manufacture of computer hard disks, a stringent requirement of low particle count exists. This is because a computer hard disk is extremely sensitive to foreign or extrinsic particles. These particles may cause damage to the computer hard disk and therefore affect the yield of the manufacturing process. Such computer products involve high-precision operations such as the minute movements of the read/write head. Thus even a small particle that is not visually detectable may cause a failure in the computer hard disk. Therefore, many computer hard disks may be rejected on the manufacturing floor because of high foreign particle contamination. Due to this stringent requirement, the screw tightening process in the manufacture of a computer hard disk cannot additionally contribute to the foreign particle count beyond certain industry standards.
Another stringent requirement often held as important is one that relates to the read/write head of a computer hard disk. Because numerous screws are used in the manufacture of the computer hard disk to fasten the parts used to form the product, inevitably the screw pick up tool is sometimes brought into close proximity with the read/write head of the hard disk. The slider head within the actuator arm of the read/write head is particularly sensitive to magnetic fields. Hence, conventional screw pick-up tools using magnets or applying magnetic fields to pick up screws are not suitable for use in such a context.
In view of the stringent requirements of the computer hard disk manufacturing industry, conventional tools involving suction means and magnetic means are often not suitable for use. For example, a tool that depends on unreliable suction means may inadvertently release or drop a screw due to the momentary loss of vacuum. If there is no loss of vacuum, the air removal device due to insufficient power may not produce a strong enough vacuum strength to hold on to a screw properly. This may result in the screw not being perpendicularly aligned for insertion into the screw hole. Cross threading may thus occur and this may introduce foreign particles into the computer hard disk. On the other hand, a conventional tool using magnetic means may not be used at all because of the inherent magnetic properties. From the foregoing, there clearly exists a need for a tool or apparatus that addresses or ameliorates at least one of the problems.
In accordance with a first aspect of the invention, there is provided an apparatus for use with a torque driver for enabling pick up of a screw and engagement of head of the screw. The apparatus includes a sleeve that longitudinally extends from and retracts into the apparatus. The apparatus further includes a gripper for gripping the screw head, the gripper being actuated by the sleeve wherein widening and closing of the gripper are dependent on extension and retraction of the sleeve.
In accordance with a second aspect of the invention, there is provided a method for picking up a screw and engaging the head of the screw using an apparatus that includes a sleeve, and a gripper. The method includes the step of extending and retracting the sleeve from and into the apparatus, respectively. The method also includes the step of and gripping the screw head by actuating the gripper with the sleeve wherein widening and closing of the gripper are dependent on extension and retraction of the sleeve.
In accordance with a third aspect of the invention, there is provided a tool that is coupled to a torque driver for picking up a screw and engaging the head of the screw. The tool includes means for gripping the screw head. The tool also includes means for engaging the screw head and means for transmitting torque from the torque driver to the engaging means and for longitudinally extending and retracting the engaging means from and into the tool, respectively.
The foregoing and other objects and advantages of the present invention will be apparent to those skilled in the art, in view of the following detailed description of the preferred embodiment of the present invention, taken in conjunction with the appended claims and the accompanying drawings.